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Viral IgG and IgA Antibodies to Cytomegalovirus (CMV) in Serum/Plasma

Published: August 9, 2026Updated: August 16, 2026

This test measures antibodies against cytomegalovirus (CMV), a common virus that can affect the immune system. It helps assess past infection and immune response.

Quick summary

["Checks for past CMV exposure and immune response in your blood."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
5124-3
Short code
CMV IgG SerPl IA-aCnc
Synonyms
CMV IgG SerPl IA-aCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
CPT
82784
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why This Test Is Done

Doctors may order this test to evaluate if you’ve been exposed to CMV, especially if you have a weakened immune system (e.g., from HIV/AIDS, chemotherapy, or organ transplant). It can also help diagnose or monitor conditions like CMV disease in newborns or transplant patients.

What to Expect Before the Test

No special preparation is needed. A blood sample is drawn from a vein in your arm, similar to other blood tests. The sample is sent to a lab for analysis.

What the Results Mean

Positive results for IgG antibodies indicate past infection and immunity. IgA antibodies may suggest recent or active infection. Together, they help determine exposure timing and immune response status.

Common Conditions Monitored

This test is critical for monitoring CMV in high-risk groups, such as pregnant women (to prevent congenital infections), transplant recipients, or those with immune deficiencies.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: CMV Antibodies Provide Critical Insights

Short name

CMV Antibody Profile (Serum/Plasma)

Frequently asked questions

What does a positive IgG result mean for me?
A positive IgG result means you’ve likely had CMV in the past and your body has developed immunity. This is usually harmless but important for monitoring if you’re at high risk (e.g., transplant patients).
Can IgA antibodies alone indicate an active infection?
Yes, IgA antibodies may appear during recent or active CMV infection, especially in people with weakened immune systems. They can help track disease progression or response to treatment.
Why would my doctor order both IgG and IgA tests together?
Combining both tests helps determine the timing of infection (IgG indicates past exposure) and whether there’s an ongoing immune response (IgA). This dual approach improves diagnostic accuracy for high-risk conditions.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy